naa a22 4500 510804691 CHVBK 20180411083411.0 cr unu---uuuuu 180411e20130501xx s 000 0 eng 10.1007/s11664-012-2371-4 doi (NATIONALLICENCE)springer-10.1007/s11664-012-2371-4 Characterization of Colloidal Quantum Dot Ligand Exchange by X-ray Photoelectron Spectroscopy [Elektronische Daten] [Ayomide Atewologun, Wangyao Ge, Adrienne Stiff-Roberts] Colloidal quantum dots (CQDs) are chemically synthesized semiconductor nanoparticles with size-dependent wavelength tunability. Chemical synthesis of CQDs involves the attachment of long organic surface ligands to prevent aggregation; however, these ligands also impede charge transport. Therefore, it is beneficial to exchange longer surface ligands for shorter ones for optoelectronic devices. Typical characterization techniques used to analyze surface ligand exchange include Fourier-transform infrared spectroscopy, x-ray diffraction, transmission electron microscopy, and nuclear magnetic resonance spectroscopy, yet these techniques do not provide a simultaneously direct, quantitative, and sensitive method for evaluating surface ligands on CQDs. In contrast, x-ray photoelectron spectroscopy (XPS) can provide nanoscale sensitivity for quantitative analysis of CQD surface ligand exchange. A unique aspect of this work is that a fingerprint is identified for shorter surface ligands by resolving the regional XPS spectrum corresponding to different types of carbon bonds. In addition, a deposition technique known as resonant infrared matrix-assisted pulsed laser evaporation is used to improve the CQD film uniformity such that stronger XPS signals are obtained, enabling more accurate analysis of the ligand exchange process. TMS, 2013 Colloidal quantum dots nationallicence surface ligands nationallicence ligand exchange nationallicence RIR-MAPLE nationallicence XPS nationallicence Atewologun Ayomide Department of Electrical and Computer Engineering, Duke University, Box 90291, 27708-0291, Durham, NC, USA aut Ge Wangyao Department of Electrical and Computer Engineering, Duke University, Box 90291, 27708-0291, Durham, NC, USA aut Stiff-Roberts Adrienne Department of Electrical and Computer Engineering, Duke University, Box 90291, 27708-0291, Durham, NC, USA aut Journal of Electronic Materials Springer US; http://www.springer-ny.com 42/5(2013-05-01), 809-814 0361-5235 42:5<809 2013 42 11664 https://doi.org/10.1007/s11664-012-2371-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11664-012-2371-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Atewologun Ayomide Department of Electrical and Computer Engineering, Duke University, Box 90291, 27708-0291, Durham, NC, USA aut NATIONALLICENCE 700 1- Ge Wangyao Department of Electrical and Computer Engineering, Duke University, Box 90291, 27708-0291, Durham, NC, USA aut NATIONALLICENCE 700 1- Stiff-Roberts Adrienne Department of Electrical and Computer Engineering, Duke University, Box 90291, 27708-0291, Durham, NC, USA aut NATIONALLICENCE 773 0- Journal of Electronic Materials Springer US; http://www.springer-ny.com 42/5(2013-05-01), 809-814 0361-5235 42:5<809 2013 42 11664 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer